Submarine boat or vessel.



No. 6941154. Patented Feb. 25, I902.

' J. P. HOLLAND.

SUBMARINE BOAT 0B VESSEL. (Apphcat on filed July 81 1901 (No Model.)

Pnorauma. Msum nou. D. c.

UNITED STATES PATENT OFFICE.

JOHN P. HOLLAND, OF NEWARK, NEW JERSEY.

SUBMARlNE -BOAT OR VESSEL.

SPECIFICATION forming part of Letters Patent No. 694,154, dated February 25, 1902.

Application filed July 31, 1901. Serial No. 70,414. (No model.)

To all whom it may concern:

Be it known that 1, JOHN P. HOLLAND, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain Improvements in Submarine Boats or Vessels, of which the following is a specification.

This invention relates to the class of boats or vessels that employ water ballast, which may be increased ordiminished at will to permit the boat to dive or to come to the surface. Such boats are commonly denominated submarine torpedo-boats, and are designed to be employed in time of war to launch torpedoes at the vessels of an enemy. One of the most important difificulties encountered in handling boats of this class, which are usually operated in bays, harbors, and estuaries along the coast, into which fresh water flows in considerable quantity, arises from the variable specific weight of the water at different points, due to different degrees of salinity, which of course produces material variation in the buoyant power of the water. In New York harbor, for example, the specific weight of the water varies at difierent points and at the same time over three hundred pounds in a volume of seventy-five tons, and this variation is found to be due to currents which change with the stages of the tides and with the direction and force of the wind. The inconvenience arising from this variation in the specific weight of the water is manifested in variations in the buoyancy of a submarine boat, and with the changing conditions of tide and wind these variations in specific weight will be'manifested at the same point in a bay or harbor at different times. Therefore if the boat be adjusted for diving with the proper percentage of reserve buoyancy when the Water in its vicinity shall have reached the maximum salinity and the ba1last-tanks of the boat are filled without alteration or adjustment for buoyancy at the minimum salinity of the water of flotation the boat will sink to the bottom, or, under the reverse conditions, where the reserve buoyancy is ad-' j usted for fresh water or for Water of flotation having the minimum salinity the boat will not dive in water of the maximum salinity or specific weight.

If the boats volume displaces seventy-five tons in fresh water, 2.1744 tons of its volume will emerge or be exposed above the surface when the boat is placed in salt water of or dinary salinity. As the volume of reserve buoyancy is only about seven per cent. of this difierence, it will be apparent that differences in the specific weight of the water in which the vessel operates must be provided for by means for changing the boats total weight correspondingly, audit is of greatimportance to be able to efiect this change quickly and in bad weather and also without the requirementof great care on the part of the person operating the boat. The present invention provides for this in the manner to be described hereinafter with reference to the accompanying drawings, wherein-- Figure Us a plan of the boat, broken away to show the water-ballast tanks in the bottom of the boat. Fig. 2 is a transverse section of the boat in the plane of the center of buoyancyof the boat indicated by line 1) in Fig. 3. Fig. 3 is a side elevation of the boat, broken away to show the ballast-tanks.

The hull or body a of the boat may be of the usual cigar shape. (Shown in Figs. 1 and 3.)

b is the propeller, c the rudders for diving, and d the conning tower or turret.

w designates in Fig. 3 the water line or level when the boat is light for surface running, with its ballast-tanks empty. The part a of the boats body above this line is called the emersed part and the part 0." below the submerged part.

-y designates the water line or level when the boat is awash and .ready for diving, the ballast-tanks being filled.

The space in the boat containing the water ballast is usually divided up into receptacles called tanks; but as this dividing is merely constructive it will beconvenient in order to make the present invention clear to consider the space within the boat for containing the necessary volume of water ballast to sink the boat in fresh water to the level of the line y as the main ballast-tank. This tankT has capacity to contain water enough to submerge the boat to the line y in fresh water-that is, to submerge the boat less the reserve buoyancy.

Because seawater has more buoyancy than fresh water there will be more buoyancy to therein will be variable.

overcome when the boa-t is operating in salt water than in fresh. Consequently an auxiliary tank 15 is provided with capacity suflicient to contain just water enough to serve when the main tank T is full to submerge the boat in sea-water to the line y or put it awash for diving.

The features are shown somewhat diagrammatically in the drawings.

In placing the tank T in the boat its center of gravity must be forward of the boats center of buoyancy such a distance that when this distance isv multiplied by the volume of the ballast-tank the product will equal that of the portion of the emersed body a forward of the boats center of buoyancy. The center of gravity cg of the tank T will be directly underthe center of buoyancy e of the emersed portion a of the boat in the transverse vertical plane indicated by the line 20 in Fig. 3. The auxiliary ballast-tank or group of tanks i will have its center of gravity in the same transverse plane (indicated, by the line 0 in Fig. 3) as the center of buoyancy of the boat when submerged to the line 1 As the tanks T and t are to be completely filled, no especial care will be required to effect the ballasting or the change of ballastthat is to say, if the boat be operating in fresh water to prepare it for diving it will only be necessary to fill the tank T from the water of flotation. If it be operating in salt water, it will only be necessary to fill both of the tanks T and t, or if 'the' boat be prepared for diving in fresh water, the tank T being full, and it moves into salt water the tank t must also be filled. On the contrary, if it be operating in salt water and be awash, with both tanks T and t full, and then moves into fresh water thewater must be blown out of the tank 15. This may be done by well-known means.

When the boat is prepared to dive in fresh or nearly fresh water and passes successively into water of greater salinity and finally into sea-water, the two tanks T and i will be filled with water the weight of which per cubic foot is less than that of sea-water, and to compensate this another small tank t is provided, this compensating tank being placed with its center of gravity in the same transverse plane with that of the tank 1. The tank t will be of such capacity as to contain water enough to compensate by weight the difference between salt and fresh water sufficient to fill the main tanks; but the volume of water Whenoperating in a mixture of salt and fresh water, a hydrometer will ormay be employed to determine the specific weight of the water of flotation. A reference to the scale of the hydrometer will indicate what quantity of water must be admitted to the tank tin order to compen-.

sate properly the difference of salinity between the water in the tanks and the water of flotation, so that the boat may dive properly and still have remaining the proper proportion of reserve buoyancy. For example, suppose the difference of displacement in volume between the boats displacement in fresh and salt water is equivalent to seventy-six cubic feet. The scale on the hydrometerwill indicate zero in fresh water and will indicate the total volume of the tank t in cubic feet say seventy-six--when submerged in normal salt water. Now if the hydrometer indicates it shows that only seventy cubic feet of water ballast need be admitted to the tank If to adjust the ballast for diving. The tank t may have an ordinary float and indicator to indicate visually the amount.

I have not deemed it necessary to illustrate the means for filling the tanks and the hydrometer and float indicator, as these are well-known devices and may be supplied by any one skilled in the art. This invention relates to the relative capacities of the tanks for diving in water of different densities.

Having thus described my invention, I claim- 1. A submarine boat having a tank with capacity, when full, for water ballast suflicient to put the boat in diving condition in fresh water, and an auxiliary tank with capacity, when both it and the main tank are full, to put the boat in diving condition in salt water, said tanks being situated with reference to the center of buoyancy of the boat substantially as set forth.

2. A submarine boat having a tank with capacity, when full, 'for water ballast suflicient to put the boat in diving condition in freshwater, said tank having .its center of gravity situated directly below the center of buoyancy of the emersed portion of the boat, and an auxiliary tank with capacity, when both it and the main tank are full, to put the boat in diving condition in salt water, said auxiliary tank having its center of gravity in the same transverse plane with the center of buoyancy of the boat, substantially as set forth.

3. A submarine boat having a tank with capacity, when full, for water ballast sulficient to put the boat in diving condition in fresh water, an auxiliary tank with'capacity, when it and the main tank are full, to put the boat in diving condition in normal salt water, and a smaller compensating tank to provide ballast to compensate the difference between the weight of salt and fresh water in the tanks, said tanks being situated with respect to the center of buoyancy of the boat, substantially as set forth.

In witness whereof I have hereunto signed my name, this 24th day of July, 1901, in the presence of two subscribing witnesses.

JOHN P. HOLLAND.

Witnesses:

PETER A. Boss, K. M. CAPLINGER.

IIO 

